Fuel cells efficiently and electrochemically convert fuel into electric current, which may then be used to power electric circuits, such as drive systems for vehicles. A fuel cell containing a proton exchange membrane is an electrochemical device that converts chemical energy to electrical energy using, for example, hydrogen or methane as fuel and oxygen/air as oxidant. A typical proton exchange membrane fuel cell is generally composed of five layers that form a fuel cell membrane electrode assembly. The membrane electrode assembly includes a solid polymer electrolyte proton conducting membrane, two gas diffusion layers, and two catalyst layers.
During operation of the fuel cell, crossover from the cathode to the anode or the anode to the cathode can occur through the membrane. This crossover of the cathode fluid, for example, can create reactions at the anode, generating a mixed potential at the anode, leading to a loss of voltage, power and efficiency. The fluid can also chemically react to form free-radicals in the membrane which degrades the membrane, increasing the potential for further crossover.